JSFiddle - React, Tailwind, and code Playground

HTML

<input id="clock" type="input" readonly="readonly" />

JavaScript

$(function() {
    var g_svros = 0;
    var clock = $('#clock');
    var tick = setInterval(function() {
        var lt = new Date(); 
        lt.setMilliseconds(lt.getMilliseconds()-g_svros);
        var ch=lt.getHours(), cm=lt.getMinutes(), cs=lt.getSeconds(); 
        if(ch==0) ch=12; 
        clock.val((ch >12?ch-12:ch)+":"+(cm<10?"0":"")+cm+":"+(cs<10?"0":"")+cs+" "+(ch>=12?"PM":"AM"));
    }, 250);
});